Song Yoon Ah (Hotelier and Lost in Love) is So Young, a seasoned veteran who just returned from suspension, while rookie Hyun Gi is played by My Girl's Lee Dong Wook in his film debut. Investigating a serial killer case, the two find clues leading them to a young girl violently murdered in a rural village ten years earlier. Plagued by external and internal ghosts, the detectives must unravel the disturbing mystery.